The invention relates to method and apparatus for securing an end cap within a chromatography cartridge.
Liquid column chromatography is a technique for identifying, separating, or purifying individual components in a subject sample. In employing the technique, a "stationary phase," such as a surface active powder, is packed into a chromatography column to form a chromatography media bed. A "mobile phase" consisting of a carrier liquid and a sample to be identified, analyzed, or purified is passed through the column. Different compounds in the sample migrate through the column at different rates, depending, e.g., on their size and degree of attraction to the stationary phase in the column. Consequently, the different compounds in the liquid emerge from the column at different times, allowing separation of the compounds in the sample. For a description of column chromatography, see McDonald et al., U.S. Pat. No. 4,250,035, entitled "Radial Compression of Packed Beds," incorporated herein by reference.
Liquid column chromatography can be carried out using a disposable cylindrical cartridge. The cartridge contains the media bed bounded axially at both ends by an end cap. The end caps are secured firmly within the cartridge to axially support the media bed. Known methods of securing the end caps include threading and the use of pre-formed retention grooves.